Methoxyflurane is non-inflammable and non-explosive at room temperature, comparable with soda lime, and can be used for general anaesthesia in a vaporizer of simple design. It can be administered most economically in a closed circuit, and the vaporizer can be used safely within the circle. The drug is satisfactory under almost all circumstances but Its slow absorption, respiratory depressant effect, and odour make it unsuitable for a minority of cases. It provides marked analgesia, good muscular relaxation, and a remarkably low incidence of vomiting. With the exception of depression of respiration, and incompatibility with epinephrine, this agent exhibits all of the advantages and none of the disadvantages of diethyl ether with an even greater margin of protection from overdose.